Home / 354.60-489.60-256.80

Finding the Fourth Proportional to 354.60, 489.60 and 256.80

Calculator

Solution

The fourth proportional to 354.60, 489.60 and 256.80 is: 354.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    354.60 : 489.60 = 256.80 : x
  2. Step 2: Convert to fraction form
    354.60/489.60 = 256.80/x
  3. Step 3: Cross multiply
    354.60x = 489.60 × 256.80
  4. Step 4: Simplify right side
    354.60x = 125,729.28
  5. Step 5: Solve for x
    x = 125,729.28/354.60
  6. Step 6: Final answer
    x = 354.57

Related Problems

Find fourth proportional to 177.30, 244.80 and 128.40
Half scale
Find fourth proportional to 709.20, 979.20 and 513.60
Double scale
Find fourth proportional to 355.60, 490.98 and 257.80
Similar ratio
Find fourth proportional to 531.90, 734.40 and 385.20
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.